Answer:
frictonal force due to the surface of irregularities
Acceleration is the rate of change of velocity, so can be calculated by:
a = v2 - v1 / t where v2 and v1 are the final and initial velocities of the object respectively and t is the time taken. Therefore the acceleration is:
a = 30 m/s - 20 m/s / 2.0 s = 10 m/s / 2.0 s = 5 m/(s^2)
Hope this helps!
B. Doldrums. I cant actually explain it i just know its the answer
Answer:
a) t = 3.2 s
b) 
Explanation:
a) El tiempo requerido para llegar al suelo se puede calcular usando la siguiente fórmula:

En donde:
: es la altura inicial = 50 m
g: es la gravedad = 10 m/s²

Entonces, el tiempo requerido para llegar al suelo es 3.2 s.
b) La rapidez de la pelota justo antes del choque es el siguiente:

En donde:
: es la velocidad inicial = 0 (dado que se deja caer en resposo)

Por lo tanto, la rapidez de la pelota justo en el momento anterior del choque es -32 m/s (el signo negativo es porque la pelota está cayendo).
Espero que te sea de utilidad!
When heat is applied to a substance/material or steel in our case, a series of changes will occur, one of which is Expansion.
Hence the hole will expand from 1cm to a diameter that is greater.
Thermal expansion refers to the expansion or contraction of the dimensions of the solid, liquid or gas when their temperature is changed.
<h3>Types of Expansion</h3>
- Linear expansion
- Areal expansion and
- Volumetric volume.
Learn more about expansion here:
brainly.com/question/1166774